How we use Hermetic, Ephemeral Test Environments at Google to reduce Test Flakiness

At Google we’ve reduced test flakiness by using ephemeral, hermetic test environments. This addresses a number of root causes (unreliable dependencies, hardware issues if communication between your system and its dependencies happens over the network, tests failing to clean up or concurrently modifying state), but it has been challenging to implement at scale, and has brought its own set of problems. Come learn about our journey!